import com.sun.security.jgss.GSSUtil;

public class Test5 {
    public static void main(String[] args) {
        System.out.println(fib(1));
        System.out.println(fib(2));
        System.out.println(fib(3));
        System.out.println(fib(4));
        System.out.println(fib(5));
        System.out.println(fib(21));
    }
    static int fib(int a){
        if(a==0){
            return 0;
        }
        if(a==1){
            return 1;
        }
        if(a==2){
            return 2;
        }
        return fib(a-2)+fib(a-1);
    }
}


